A fibre feeding device

(54) (56) (57)

PATENT INVENTOR INVENTOR

NAME

Telefonaktiebolaget LM Ericsson, 126 25 Stockholm SE Erik Bergqvist, Bergsjö SE, Bertil Olsson, Näsviken SE Ericsson Microelectronics AB

Optical fiber feed device

CALLED PUBLICATIONS: - SUMMARY:

The present invention relates to a feeding device for one or more cohesive optical fibers into a tube or the like. In order to be able to easily handle the feeding device, it has been formed with a channel (26) into which a beam (22) can be inserted with one or more longitudinal bi-channel channels (29), each bi-channel channel having a cross-section adapted to a certain type of optic fiber. In the lower surface of the groove, there are holes (25, 27) near the trailing edge and near the leading edge for supplying and removing compressed air for propulsion of the optical fiber. With the optic fiber placed in the bi-channel duct of the beam, when compressed air is supplied through the holes in the trailing edge, propulsion of the optical fiber in the bi-duct channel is obtained, because the bi-duct channel will

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The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.

513 045 i

TECHNICAL FIELD

The present invention relates to a device for feeding fibers such as one or more preferably cohesive optical fibers into a tube or the like.

BACKGROUND OF THE ART

Installation of an optical fiber with bi-lock technology is known in the past. In order to be able to inflate an optofibre or more optofibre in air with an optofibre tape in a tube or the like, friction between the optofibre and the inside of the tube must be very low, the static electricity generated is negligible and the air resistance must be sufficiently large for the optofibre to be fed even at moderate propulsion air speeds. The solution to this problem has hitherto been to coat the optical fiber 1 or the optical fiber band with a diameter increasing layer 2 into which friction reducing material has been added. If several joined optical fibers 3, 4 have been required, these may have been arranged in a rotationally symmetrical bundle to obtain the same bending resistance in all planes and provided with a diameter-increasing layer 5, 6 of, for example, glass beads. In order to be able to use fiber optic tape / ribbon technology 7-9 with the advantages that this could entail in welding and contacting without introducing an extra material to obtain a rounded cross section, reducing friction and increasing the air resistance, for example, a thin wire 10 of for example kevlar around the optical fiber band. This wire can then be easily removed at the ends of the fiber when welding or contacting is to take place. See Figures 1A-G.

When an optofibre 11 or an optofibre / ribbon is to be supplied with compressed air in a tube, the optofibre is introduced into a pressurized space 12 of a feeder device connected to the tube 13 or conduit / duct into which the optofibre is to be blown, some force must be applied to

513 045 overcomes the blowout force acting on the optical fiber in the opposite direction to the feed direction. In several systems this has been solved by passing the optical fiber 11 between two feeder rollers 14, 15 with soft outer coating. These wheels may be electrically driven, but may also be driven by the pressurized air used for propulsion of the optic fiber so as not to destroy the optic fiber, if for some reason this would be stopped by some obstacle in the tube. A pressure sensing device 16 may be present in the space 12 to detect any pressure changes that might occur at a stop. A feeding device for said feeding method will be quite complicated and, in addition to compressed air for the propulsion of the optical fiber, also requires the supply of electrical energy. See Figure 2.

The resulting blowout force can be partially overcome the ejector action from the applied leakage flow 18 with the opto fiber 11 the downstream side air velocity being allowed to pass designed as the pressure becomes high and the bias tube can be provided with control when introducing into the outlet valves thus driving force. The leakage flow of the leakage flow.

the bias tube one to for there

On the compressed air 17, through a bias tube 19, a venturi tube, low.

The adjustable Optofiber further provides a lower pressure in the bias tube, which can reduce the possible bias length. See Figure 3.

DISCLOSURE OF THE INVENTION

In order to be able to easily handle a feeding device formed with a bladder channel for feeding one or more optofibre in a tube or the like, the bladder duct of the feeder device has been opened openable for different types of optofibre to be fed. The feeding device consists of a frame with a groove into which a beam can be inserted with one or more longitudinal bi-channel channels, where each bladder channel has a cross-section adapted to a specific type of optic fiber. In the track

513 The lower surface of the 045 is located near the trailing edge and near the leading edge holes for supplying and removing compressed air for propulsion of the optical fiber. With the optical fiber located in the beam's bias duct and the beam positioned in the groove / channel of the air supply, through the holes in the trailing edge the propulsion fiber is propelled into the bias duct, because the bi-duct duct will act as a venturi tube, where a small leakage flow into the duct through the ejector fiber is transmitted. in a bi-tube. Because the beam is detachable and provided with different groove sizes, the feeding device can be used for different types of optical fiber and also allows feeding of pre-contacted optical fiber. The construction also allows non-circular cross-sectional optical fiber strips to be blown with the feed device, since the bi-channel channels can be formed with a rectangular cross-section.

The invention will now be described in more detail with the aid of a preferred embodiment and with reference to the accompanying figure sheets.

DESCRIPTION

Figures 1A-G show cross-sections of conventional optical fibers with external means for reducing friction and / or increasing air resistance and a wrapped optical fiber ribbon cable.

Figure 2 shows an optical fiber feed device.

Figure 3 shows the principle of optofiber feed with venturi technology.

Figures 4A-C show a feed device for an optical fiber according to the invention and cross sections thereof.

PREFERRED EMBODIMENTS

Figures 4A-C show schematically how a feeding device 21 according to the invention is formed with a removable beam 22 for feeding different types of optical fiber cable 23.

513 045 adjustable compressed air connection 24, formed as a pistol grip, is connected to one end of the supply device.

With the compressed air connection, compressed air can be supplied to one or more holes 25 at one end of the lower surface of a duct 26 in the supply device. At the other end of the channel of the feeder one or more possibly adjustable holes 27 are connected to an area outside the feeder for venting. In the beam 22 of substantially square cross-section arranged to be inserted in the channel 26 on the body 28 of the feeder 28, there is a milled groove 29 on at least one longitudinal side, where the milled groove is arranged to act as a blow channel for an inserted optical fiber with the beam located in the body of the feeder. . The cross-section of the bi-channel channel 29 is thereby adapted to be able to specifically fit an optical fiber or an optical fiber band for its feeding with the beam placed in the body. In order to be able to fix the beam 22 in the channel 26 on the body 28, it is provided with threaded holes 30, 31 in its upper side, into which holes are inserted at least two clamping screws 32, 33. With the clamping screws, the position of the beam in the body channel can be controlled, ie the bi-channel channel is opened. for inserting an optical fiber cable or closed for the fiber optic cable feed. A spring 34 arranged between beam and frame can simplify the handling of the optical fiber by lifting the beam from its abutment surface with: out or added to it.

spring force and. An optofibre light tube tube 35 can easily be taken up the fiber optic can be easily attached to the frame between the frame feeder by squeezing and the beam 22. To one and the same frame beams of different channel cross sections can be used, whereby feeding of different cable cross sections can be carried out.

To further simplify an installation of optical fibers, the feeder device may be provided with a simple holder formed as a retractable arm 36 for a drum 37 or the like with wound optical fiber. With a feeder device according to the invention connected to the drum with optical fiber can

513 045 easily one person install optofibre. With the feeder device, a pre-contacted optical fiber cable of predetermined length can be fed into a tube, whereby if the pre-contacting is located on the front end of the fiber optic cable the beam is lifted for exposing the bi-channel channel. If the pre-contact is located on the rear end, the drum can support this and an optofiber cable of a certain length, whereby, after inserting the optofiber cable into the bias tube, a finished optofiber connection is obtained which can be arranged to be directly attached to an already arranged outlet such as a wall outlet in a housing outlet.

On the arm 36 holding the drum 37, there may be blown length of optical fiber a recording device 38 which, for example, optically detects the side of the drum rotation for unwound optical fiber. braking device the optofiber of activation, the bi-channel can at a stop i for registration of turns of the optofiber and may furthermore

On the arm r

a mark on the drum's determination of the number of lengths of winding compressed air driven when or if

39, someone was guided by the pressure change that occurs in the feed of the optic fiber.

which slows down the drum reason is stopped. braking device

The invention is, of course, not limited to the embodiment described above and to the embodiment shown in the drawing, but can be modified within the scope of the appended claims.

513 045